Henry Becker directs trades in shares of MetLife on Thursday at the New York Stock Exchange, where investors watched stocks make substantial gains despite a surge in oil prices because of the turmoil in Libya and neighboring countries. (Associated Press)

Specialist Thomas Facchine (left) directs trades from his position on the floor of the New York Stock Exchange on Tuesday, when the Dow closed above 12,000 for the first time in 2½ years. (Associated Press)

A television monitor shows President Obama and Michele Obama as he presides over a national moment of silence, while specialists on the trading floor of the New York Stock Exchange observe the occasion for severely injured Arizona Rep. Gabrielle Giffords and the people who were killed during an assassination attempt against her, Monday, Jan. 10, 2011. (AP Photo/Richard Drew)

ASSOCIATED PRESS
Traders Gregory Grassi (left) and Peter Tuchman confer on the floor of the New York Stock Exchange on Wednesday. The Dow Jones industrial average rose nearly 250 points, its biggest gain since Sept. 1.

General Motors Co. CEO Daniel Akerson sits in the driver's seat of a 2011 Chevrolet Camaro in front of the New York Stock Exchange following GM's initial public offering, Thursday, Nov. 18, 2010 in New York. Duncan Niederauer, CEO of NYSE Euronext, is seated at right. (AP Photo/Mark Lennihan)